Optical displays are often hard to view in bright surroundings. For the purpose of counteracting this and heightening the contrast between the display and the surroundings, the light efficiency of the means must be increased which entails that more energy is consumed. Another possibility consists in the provision of shielding elements which are intended to shield the display from extraneous light incident on it. As a rule, such shielding means restrict the viewability of the display or shield it only insufficiently from incident extraneous light, such as, e.g., sunlight. Shielding the display from variable extraneous light, e.g. with a moving incident angle, often turns out to be difficult.
DE-T-693 26 611 discloses a device for preventing a false light phenomenon in a signal lamp, said device being provided between a light source and a cover lens and comprising a pair of complex spherical lenses in a specific arrangement and a shielding element positioned between said pair of lenses and having light-transmitting holes.